JP2017120691A - X-ray tube apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-ray tube apparatus capable of efficiently cooling an X-ray tube.SOLUTION: An X-ray tube apparatus 1 comprises an X-ray tube 3 having an anode unit against which an electron beam discharged from a cathode impinges to generate X-rays, a tube container 5 housing the X-ray tube 3, a refrigerant supply path 29 for supplying refrigerant into the anode unit and the tube container 5 of the X-ray tube 3, a high-temperature refrigerant discharge path 25 for discharging, to the outside of the tube container 5, high-temperature refrigerant after cooling the anode portion, a low-temperature refrigerant discharge path 33 for discharging, to the outside of the tube container 5, refrigerant that has cooled the inside of the tube container 5 and is lower in temperature than the high-temperature refrigerant, and a main heat exchanger 27 that connects only the high temperature refrigerant discharge passage 25 to cool the high temperature refrigerant of the high temperature discharge passage.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to an X-ray tube apparatus.

  Patent Document 1 discloses a technique in which a heat exchanger is provided in a refrigerant circulation circuit that circulates a refrigerant in a tube container containing an X-ray tube, and the heat exchanger is cooled by a refrigeration cycle.

JP 2001-185396 A

  However, the refrigerant circulation circuit circulates in the tube container to cool the X-ray tube, or there is a disadvantage that the X-ray tube having a temperature difference depending on the site cannot be efficiently cooled.

  An object of the present embodiment is to provide an X-ray tube apparatus capable of efficiently cooling the X-ray tube.

  An X-ray tube apparatus according to an embodiment includes an X-ray tube having an anode portion that generates X-rays when an electron beam emitted from a cathode collides, a tube container housing the X-ray tube, and the X-rays A refrigerant supply path for supplying refrigerant into the anode part of the tube and the tube container, a high-temperature refrigerant discharge path for discharging the high-temperature refrigerant after cooling the anode part to the outside of the tube container, and a refrigerant for cooling the inside of the tube container A low-temperature refrigerant discharge path for discharging a refrigerant having a temperature lower than that of the high-temperature refrigerant to the outside of the tube container, and a main heat exchanger for cooling only the high-temperature refrigerant by connecting only the high-temperature refrigerant discharge path. X-ray tube device.

FIG. 1 is a circuit diagram showing a schematic configuration of an X-ray tube apparatus according to an embodiment.

  An embodiment of the present invention will be described below with reference to the drawings. It should be noted that the disclosure is merely an example, and those skilled in the art can easily conceive of appropriate changes while maintaining the gist of the invention are naturally included in the scope of the present invention. In addition, for the sake of clarity, the drawings may be schematically represented with respect to the width, thickness, shape, etc. of each part as compared to actual aspects, but are merely examples, and The interpretation is not limited. In addition, in the present specification and each drawing, components that perform the same or similar functions as those described above with reference to the previous drawings are denoted by the same reference numerals, and repeated detailed description may be omitted as appropriate. .

  FIG. 1 is a circuit diagram schematically showing an X-ray tube apparatus 1 according to the present embodiment. As shown in FIG. 1, the X-ray tube apparatus 1 includes an X-ray tube 3, a tube container 5 that houses the X-ray tube 3, and a cooling unit 7.

  The X-ray tube 3 is a transmission cooling type rotary anode X-ray tube, and is fixed to an anode fixing shaft 9 fixed to an anode portion (not shown) that generates X-rays by collision of an electron beam emitted from a cathode. A stator coil 13 and a stator insulator 14 are provided on the outer periphery of the anode fixed shaft 9 to generate a rotating magnetic field for rotating the anode portion through an insulating cylinder 11.

  The anode fixing shaft 9 is conducted with heat of the anode portion through the liquid metal bearing surface, and a cooling passage 15 for introducing a refrigerant into the anode fixing shaft 9 to cool the anode fixing shaft 9 is formed. A refrigerant introduction path (refrigerant introduction pipe) 15 a is inserted into the cooling passage 15, and the refrigerant introduced from the refrigerant introduction path 15 a cools the anode fixing shaft 9 through the cooling passage 15. The refrigerant is insulating oil.

  Further, on the refrigerant introduction side of the anode fixed shaft 9, a refrigerant distribution cover 17 mainly formed of a resin such as polycarbonate is attached. In the refrigerant distribution cover 17, a refrigerant introduction path 15 a is inserted and a refrigerant outlet path 19 communicating with the cooling path 15 is formed. Further, the refrigerant distribution cover 17 is formed with a distribution path 21 for introducing a part of the refrigerant into the tube container 5 from the refrigerant introduction path 15a.

  The tube container 5 is filled with refrigerant (insulating oil) together with the X-ray tube 3.

  The cathode side high voltage wiring 20 of the X-ray tube 3 is connected to a cathode side high voltage socket 23, and the anode side high voltage wiring 22 is connected to an anode side high voltage socket 24.

  In addition, the tube container 5 has an airtight structure, and absorbs an increase in pressure in the tube container 5 due to volume expansion due to a temperature rise of the refrigerant (insulating oil) filled in the tube container 5. An air basin 28 mainly composed of nitrile butadiene rubber or the like is provided. The air basin 28 keeps an airtight seal through the air conduction hole 26, and makes the inside of the tube container 5 equal to the atmospheric pressure.

  Next, the cooling unit 7 will be described.

  The cooling unit 7 discharges the high temperature refrigerant at the outlet side of the high temperature refrigerant discharge path 25, the main heat exchanger 27, and the main heat exchanger 27 connected to the cooling path 15 of the anode fixed shaft 9 via the refrigerant outlet path 19. A refrigerant supply path 29 connected to the path 25 and a control unit 30 are provided, and the refrigerant supply path 29 is connected to the refrigerant introduction path 15a. The high-temperature refrigerant discharge path 25, the refrigerant supply path 29, the refrigerant introduction path 15a, and the cooling path 15 constitute a refrigerant circulation circuit.

  The high-temperature refrigerant discharge path 25 is led out of the tube container 5 and is connected to a main heat exchanger 27 provided outside the tube container 5, and the high-temperature refrigerant exchanges heat with the main heat exchanger 27. It is cooled by that.

  The main heat exchanger 27 is a brazing plate type heat exchanger, and as the heat exchange medium, cooling water or cooling air, alternative chlorofluorocarbon cooled by a heat pump, carbon dioxide gas, or the like is used. In this embodiment, Cooling water is used, and a cooling water pipe 31 is connected to the main heat exchanger 27. The temperature of the cooling water or cooling air can be room temperature. The main heat exchanger 27 has an outer peripheral surface covered with a heat insulating cover 34.

  On the other hand, the tube container 5 is connected with a low-temperature refrigerant discharge path 33 for leading the internal refrigerant. The refrigerant temperature in the tube container 5 is lower than the refrigerant flowing through the high-temperature refrigerant discharge path 25 that receives heat from the anode fixed shaft 9.

  The low-temperature refrigerant discharge path 33 is connected to the tube container 5 in the tube container 5 on the air basin 28 side of the high-temperature refrigerant discharge channel 25 and in the vicinity of the air basin 28.

  In the high-temperature refrigerant discharge path 25, a refrigerant merging portion 35 connected to the low-temperature refrigerant discharge path 33 and where the low-temperature refrigerant merges is provided on the outlet side of the main heat exchanger 27, and the refrigerant merging section 35 is connected to the refrigerant supply path 29. It is connected to the. A main circulation pump 37 is provided in the refrigerant supply path 29, and the main circulation pump 37 is a brushless DC pump, and a suction port is provided on the downstream side of the refrigerant junction 35.

  The refrigerant supply path 29 is connected to an auxiliary refrigerant supply path 39 provided in parallel. The auxiliary refrigerant supply passage 39 is provided with an auxiliary circulation pump 41 and an auxiliary heat exchanger 43 on the downstream side of the auxiliary circulation pump 41. The auxiliary heat exchanger 43 is a brazing plate heat exchanger, to which a cooling pipe 45 for supplying a heat exchange medium is connected, and the auxiliary heat exchanger 43 is cooled by a heat exchange medium supplied from the cooling pipe 45. Yes. The heat exchange medium supplied from the cooling pipe 45 is cooling water or cooling air like the main heat exchanger 27.

  The auxiliary circulation pump 41 also has the refrigerant confluence portion 35 side as a suction port. In addition, a check valve 44 is provided on the discharge side of the auxiliary circulation pump 41 and on the outlet side of the auxiliary refrigerant supply passage 39 to prevent the refrigerant from flowing back from the refrigerant supply passage 29 to the auxiliary refrigerant supply passage 39. ing.

  The low-temperature refrigerant discharge path 33 is provided with a flow rate adjusting valve 47 on the upstream side of the refrigerant merging section 35 so that the amount of the low-temperature refrigerant merged in the refrigerant merging section 35 can be adjusted.

  The main circulation pump 37 and the auxiliary circulation pump 41 are each connected to a power source 49.

  Next, the control unit 30 will be described.

  The control unit 30 includes a temperature detection unit 51 of the tube container 5 and a pump drive control unit 53. The pump drive control unit 53 controls the drive of the main circulation pump 37 and responds to a detection signal of the temperature detection unit 51. Thus, the driving of the auxiliary circulation pump 41 is controlled.

  The temperature detection unit 51 is a thermostat, and is input when the temperature of the tube container 5 becomes higher than a predetermined temperature. When the pump drive control unit 53 receives an input signal of the temperature detection unit 51 while the main circulation pump 37 is being driven. When the auxiliary circulation pump 41 is driven and the temperature of the tube container becomes lower than the predetermined temperature, a cutting signal is received and the driving of the auxiliary circulation pump 41 is stopped.

  Next, the operation and effect of the X-ray tube apparatus 1 according to the embodiment will be described.

  In the X-ray tube apparatus 1 according to the embodiment, the main circulation pump 37 is driven in response to a drive signal from the control unit 30. Thereby, a part of the refrigerant is supplied from the refrigerant supply path 29 through the refrigerant introduction path 15 a to the cooling passage 15 of the anode fixed shaft 9, and the other part of the refrigerant is supplied into the tube container 5 through the branch path 21.

  In the cooling passage 15 of the anode fixing shaft 9 where heat is transmitted from the anode part, the heat transfer surface is a high temperature close to 200 ° C., and the refrigerant temperature after cooling rises to near 100 ° C. to become a high temperature refrigerant. The high-temperature refrigerant flows into the main heat exchanger 27 through the high-temperature refrigerant discharge path 25 through the refrigerant outlet path 19 while being separated from the refrigerant in the tube container 5, and is heat-exchanged with the cooling water.

  When the cooling water of the main heat exchanger 27 is room temperature (25 ° C.) and the temperature of the high-temperature refrigerant exchanged with the main heat exchanger 27 is 100 ° C., the temperature difference ΔT = 75 ° C., and the temperature difference is large. Therefore, even when the overall average temperature of the refrigerant in the tube container 5 is low with a relatively small heat exchanger, a large cooling efficiency can be obtained.

  In addition, in the main heat exchanger 27, the inflow side of the piping can be brought forward early by heat exchange with a high-temperature medium after X-ray imaging (after the X-ray tube is activated) even if the average temperature of the entire tube container 5 is low. Although it may rise to 80 ° C. or more, since it is covered with the heat insulating cover 34, it is possible to prevent workers and the like from coming into contact with the high temperature part.

  The refrigerant in the high-temperature refrigerant discharge path 25 is heat-exchanged by the main heat exchanger 27 and lowered in temperature, and then merged with the low-temperature refrigerant led out from the tube container 5 by the low-temperature refrigerant discharge path 33 at the refrigerant junction 35, It is sent to the refrigerant supply path 29.

  Further, when the refrigerant temperature of the low-temperature refrigerant derived from the tube container 5 is 45 ° C. or less, for example, the pump drive control unit 53 of the control unit 30 drives only the main circulation pump 37 and the refrigerant junction unit 35 The merged refrigerant is pumped to the refrigerant supply path 29.

  If a high-temperature refrigerant is sucked into the main circulation pump 37 or the auxiliary circulation pump 41, there is a possibility that the thermal protection of the pump operates or the bearing life of the pump head is remarkably shortened. The pump 37 and the auxiliary circulation pump 41 are disposed on the outlet side of the main heat exchanger 27, and the low-temperature refrigerant discharge path 33 is merged on the outlet side of the main heat exchanger 27, so that the main circulation pump 37 and the auxiliary circulation pump 41 are combined. Because these are connected to the suction side of the pump, when these pumps are started, the pump back pressure side becomes negative pressure due to the viscosity and inertial force of the refrigerant, causing cavitation, making the pump startup extremely difficult and reducing the flow rate. Can be prevented.

  Furthermore, the refrigerant temperature sucked by the main circulation pump 37 and the auxiliary circulation pump 41 is also adjusted by adjusting the ratio of the refrigerant to be merged by the flow rate adjustment valve 47.

  Since the low-temperature refrigerant discharge path 33 is in the vicinity of the air basin 28, the suction side of the main circulation pump 37 and the auxiliary circulation pump 41 is always maintained at a pressure close to atmospheric pressure, and a negative pressure is suppressed.

  In the present embodiment, when the temperature detection unit 51 of the control unit 30 causes the temperature of the tube container 5 to be equal to or higher than a predetermined temperature (for example, 45 ° C.), the pump drive control unit 53 drives the auxiliary circulation pump 41, The auxiliary heat exchanger 43 can also be cooled to increase the cooling capacity. When the average temperature in the tube container 5 is low, the viscosity of the refrigerant is high. When the two pumps of the main circulation pump 37 and the auxiliary circulation pump 41 are driven, the flow rates of the low-temperature refrigerant discharge passage 33 and the flow rate adjustment valve 47 are increased. In this case, only the main circulation pump 37 is driven because there is a possibility that the suction side pressure of the pumps 37 and 41 is too low. Thus, by providing the temperature detection unit 51 that manages the temperature of the tube container 5, control according to the refrigerant temperature in the tube container 5 can be achieved.

  The above-described embodiment has been presented as an example, and is not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  For example, without providing the auxiliary refrigerant supply path 39, the auxiliary circulation pump 41, and the auxiliary heat exchanger 43, the control unit 30 performs control to increase the output of the main circulation pump when the temperature detection unit 51 detects a predetermined temperature, It is good also as what saves energy generation while preventing generation | occurrence | production of the cavitation by the high temperature of a refrigerant | coolant.

  The X-ray tube 3 can be applied not only to a rotary anode X-ray tube but also to a fixed anode X-ray tube.

  The high-temperature refrigerant discharge path 25 for discharging the high-temperature refrigerant having cooled the anode part may be a high-temperature refrigerant discharge part of the high-temperature part of the vacuum envelope wound around the anode side of the metal vacuum envelope.

  The flow rate adjustment valve 47 may be provided in the high-temperature refrigerant discharge path 25.

  The ratio adjustment of the refrigerant to be merged in the refrigerant merge section 35 may be adjusted by the thickness of the high temperature refrigerant discharge path 25 or the low temperature refrigerant discharge path instead of the flow rate adjustment valve 47.

  DESCRIPTION OF SYMBOLS 1 ... X-ray tube apparatus, 3 ... X-ray tube, 5 ... Tube container, 25 ... High temperature refrigerant | coolant discharge path, 27 ... Main heat exchanger, 28 ... Air basin, 29 ... Refrigerant supply path, 33 ... Low temperature refrigerant discharge path, 34 ... heat insulation cover, 35 ... refrigerant junction, 37 ... main circulation pump, 39 ... auxiliary refrigerant supply path, 41 ... auxiliary circulation pump, 43 ... auxiliary heat exchanger, 47 ... flow control valve, 51 ... temperature detection unit.

Claims (7)

An X-ray tube having an anode part that generates X-rays by colliding with an electron beam emitted from the cathode;
A tube container containing the X-ray tube;
A refrigerant supply path for supplying refrigerant into the anode part of the X-ray tube and the tube container;
A high-temperature refrigerant discharge path for discharging the high-temperature refrigerant after cooling the anode part to the outside of the tube container;
A refrigerant that has cooled the inside of the tube container, and discharges a refrigerant having a temperature lower than that of the high-temperature refrigerant to the outside of the tube container; and
An X-ray tube device comprising: a main heat exchanger that connects only the high-temperature refrigerant discharge path and cools only the high-temperature refrigerant.   The refrigerant | coolant merge part which merges the refrigerant | coolant cooled with the said main heat exchanger, and the refrigerant | coolant of the said low-temperature refrigerant | coolant discharge path is provided, The mixed refrigerant after joining by the refrigerant merge part is supplied to the said refrigerant | coolant supply path. X-ray tube device.   The X-ray tube apparatus according to claim 1, wherein the refrigerant supply path includes a main circulation pump that sends out the refrigerant, and the main circulation pump has a suction port on an outlet side of the main heat exchanger.   The refrigerant supply path includes an auxiliary refrigerant supply path provided in parallel on the downstream side of the refrigerant merging section, an auxiliary circulation pump and an auxiliary heat exchanger provided in the auxiliary refrigerant supply path, a temperature detection unit of the tube container, An X-ray tube apparatus according to claim 2, further comprising a control unit for an auxiliary circulation pump, wherein the control unit drives the auxiliary circulation pump when the temperature detection unit detects a predetermined temperature or more.   The said high temperature refrigerant | coolant discharge path or the said low temperature refrigerant | coolant discharge path is equipped with the flow control valve, and can adjust the mixing amount of the said high temperature refrigerant | coolant mixed with the said refrigerant | coolant mixing part, and the said low temperature refrigerant | coolant. X-ray tube apparatus as described in the item.   The tube container includes an air basin provided on a container wall surface to adjust a pressure in the container, and the low-temperature refrigerant discharge path has a connection port connected to the tube container on the air basin side of the high-temperature discharge path. Item 6. The X-ray tube device according to any one of Items 1 to 5.   The said main heat exchanger is an X-ray tube apparatus as described in any one of Claims 1-6 provided with the heat insulation cover which covers an outer peripheral surface.

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